Automatic transmission



Sept. 9, 1958 J. KNOWLES- AUTOMATIC TRANSMISSION Filed Aug. 15, 1956 United States AUTOMATIQ TRANSMISSION Application August 15, 1956, Serial-No; 604,174

14;Claims. (Cl.*-'74--.677)

My invention relates'generally-to a new and improved .power transmission mechanism and -more --particu1ar ly to a multiple speed power transmission mechanism with control means for effecting an automatic shift from one gear ratio to another.

' According-to a principal feature of my invention, provision is made for transmitting power from -a driving portion of the transmission to a driven portion through va planetary reduction gear unit and for controlling the 'relative'motion of the gear elements of the gear unit to effect forward and reverse operation, said shift controlling means including a direct drive clutch for transmitting power directly 'from'the driving portion tothe driven portion of the transmission. I

According toanother feature of my invention the'transmission includes a hydrokinetic torque converter unit *havingapump, a turbine and -a reactor, the torque. acting on thelatter during operation being in. adirection which is opposite to the direction of the. torque acting on the "turbine, said shift controlling meansbeing further adapted to selectively brake the reactor member during forward drive operation while permitting the delivery of .power fromthe turbine to the power input member of the gear unitirand tobrake the turbine while permitting the reactor to transmit a reversetorque to .the gearunit to obtain ;.a reverse. drive.

.In general, ;the direct drive clutch feature of my imchange in the ratio of the static pressure exist ing. the converter toms circuit -,to the. static pressure-acting exterrnally on .the pump,.m ember. ,By preference, the: ,pump

.,member .and the above mentionedrconverter housing vdefine a. cavitywithin whichfluid may .beadmitted to ro- .duce. the ..above mentioned externally acting. static pressure,.said-. fluid also (creating a centrifugal pressure force awhichactsonthe pumpmernber and whichneutralizes the ,opposedcentrifugal pressure force exerted :on the pump member by the, fluid within theconverter torus circuit.

The provision of an improvedvhydrokinetic torque cenverter transmission of the .typeabove setforth. being .thei-overall transmission gear reduction ratio wherein one of the members of the torque converter .unit is:adap1edto .form aportionof the clutch assembly.

.It isa further object fmyinvention to ,provide, a, trans {mission .asssetforthuabove wherein the ,clutch feature is characterized by its simplifiedconstruction and may be resented Sept. 9 was ice incorporated into a variety of converter transmission assemblies by conventional manufacturingand assembly techniques. 7

.For the purpose of more particularly describing the principal features of my invention, reference will be made to the accompanying'drawing which shows, a cross sectional assembly view of the transmission.

The hydrokinetic torque converter .unit is designated in the drawing by numeral 10 andthe planetary gear unit is generally designated by numeral 12. The hydrokinetic torque converter unit '10 and the gear unit 12 are enclosed by a common transmission housing 14 which may be secured to a vehicle engine in aconventional manner. The engine crankshaft is shown in part'inthedrawing at 16 and it is provided with a boltfiahge 18 to which a flexible fiy wheel 20 may be secured, suitable bolts'ZZ being provided for this purpose. The periphery of the fly wheel 20 may carry an external, ring gear 24 which is adapted'to drivably engage a starter-pinionassociated :with a conventionalelctric engine ---starter motor.

ging formed in the transverse:wall.;26,. asuitable abushing 42 being provide'd for this purpose. A positive driving connection between -;the external pump H gear 36. land. the .Sleeve 46 is formed as shownat 44.

,The other end of the sleeve .40. is positively-connected to the hub of aturbine shroud. 46 positionedin the converter housing, saidconnectionbeing indicated at 48. :The outer periphery of the shroud ,46 is formed with a flange 50 to which a housing portion or drum 5 2,is joined .bY means of bolts 54,- the drum-51in .turmbeingsecured to;theflexible fly wheel'20 by means of bolts-5 6] I The hydrokinetic unit 10 includes a bladed turbine ,member 58 having a hub 60 with an axial extension 62 received within the sleeve 40, a suitable bushing 6 4 being interposed between the extension 62 -on the, sleeve .40

rtopermit relative rotation therebetween. Theextension 62 is positively splined to a sleeve shaft 66 whichextends .totsun gear 68 and which is integrally; joined thereto as indicated.

The hydrokinetic converter unit; 10 further includes-a pump member 70 which cooperates with the turbine memberSStodefine a torus fluid circuit. Ihe pumpcmember 7.0 is received within the aforementioned Qdrurh,52 audit is formed withaperipheral shoulder 'Zzwithin whichv is formed a plurality of axially extending vpilot opening;

74. Aseparate pilot. shaft'76 is received Within each opening 74 and by preference the shafts 76 form a part ,ofthe bolts .56. The cavity defined by the opening 74 communi- Gates with the exterior throughv a port 78. The drum 52- is formed with a tranverse Wall, 80 which may. be

I piloted atthe center ,thereofwithin a suitable pilot openingYSZIOi-med in the engine crankshaft 16. The.,.wa1l .80 is' further formed with. an internally situated friction clutch surface 84.

A: second friction clutch surface 86 is jforined on the e te i r. of pu p" emb 7 in juxt p se r lat ns ip withrespectto the surface 84,and an annularfriotion disc 88 is disposed, between the clutch surfaces- .84 and ;86,,said disc 88 preferably including suitable lining materialon either side thereof as indicated.

Theclutch disc 88 is joined to a. hub member,9;0 by

means of a conventional damping spring connection generally indicated by numeral 92 said hub being journaled within an adapter 94 which is centrally secured to the wall 80, a suitable bushing 96 being located between the cooperating portions of the hub member 9%) and the adapter 94. a

The pump member 70 is centrally apertured at 98 to receive therein the hub member 90, said pump member 70 being adapted to move axially with respect to hu member 98. s

The hydrokinetic converter unit 18 furtier includes a reactor member 100 situated between the entrance to the pump 70 and the exit of the turbine member 58, and it includes a hub comprised of a pair of axially spaced adapters 182 and 104 which are supported by an inner race 166 of a one-way brake assembly, said assembly further including an outer race 108 and a plurality of interposed one-way clutch members 110. The inner race 106 is positively splined to sleeve shaft 112 extending to a carrier 114 of the planetary gear unit 12. Another sleeve shaft 116 is concentrically disposed within sleeve shaft 112 and it is positively splined at one end thereof to the hub member 90 and at the other end thereof to a power output shaft 118.

Referring more particularly to the planetary gear portions of the transmission mechanism, the aforementioned sun gear 68 is centered in adjacent relationship with re spect to a second sun gear 120 integrally joined to the power output shaft 116. The carrier 114 is comprised of a pair of gear supporting portions 122 and 124 which may be joined in a suitable fashion by bolts 126 as illustrated. The carrier portion 124 is journaled on a stationary adapter 128 secured to an end wall 130 of the transmission casing 15 and the carrier portion 122 is rotatably journaled on an extension 132 of the hub of a brake member 134, said brake member in turn being journaled on an extension 136 of the aforementioned stationary pump casing 38. A compound planet pinion 138 is rotatably supported by the carrier portions 122 and 124 by means of a pinion shaft 140 extending from the carrier portion 122 to the carrier portion 124, suitable needle bearings 142 being interposed between the planet pinion 138 and the shaft 140. The pinion 138 includes a first gear portion 144 engageable with the aforementioned sun gear 138 and a gear portion 136 engageable with the sun gear 120.

The end wall 130 is centrally apertured to receive therein a power output shaft 118 and it is recessed at 148 to define a second pump chamber which is adapted to accommodate a pair of intermeshed pump gears 150 and 152.

The carrier 114 is formed with a brake drum surface 154 and a brake band 156 encircles the same. Similarly, the brake member 134 is formed with a peripheral brake surface 158 about which is positioned a brake band 160. The brake bands 156 and 160 may be selectively energized for the purpose of obtaining a loW gear reduction ratio or a reverse reduction ratio as desired.

It will be apparent that the aforementioned pump elements 34 and 36 supply a fluid pressure which is dependent upon engine speed since the input gear element 36 is drivably connected to the engine crankshaft 16. Also, it is apparent that the rear pump gears 150 and 152 are adapted to supply a pump pressure which is dependent only upon vehicle speed. These separate pump pressures may be utilized in a control circuit for controlling the operation of the planetary gear elements and the clutch shown at 84, 86, and 88.

In operation, it is possible to obtain either of two forward drive reduction gear ratios in addition to the reverse ratio. During forward drive, power is delivered from the engine crankshaft 16 through a flexible fly wheel 20 and through the connections 76 to the pump member 70. This creates a torus flow which causes torque to be imparted to the turbine member 58 and to the sun gear 68 which is joined to the hub 66 of the turbine member 58 by means of sleeve 66. The brake band 156 is energized during low speed operation thereby holding the carrier 114. The sun gear 68 thus drives the planet gear portion 134 which in turn causes the planet gear portion 136 to drive the sun gear 129 and the integrally joined power output shaft 118. According to one preferred embodiment of my invention, the gear reduction ratio during low speed operation is 1.59 so that the overall torque multiplication ratio is equal to 1.59 times the converter torque ratio. To obtain direct drive, the ratio of the static pressure in the torus circuit defined by the converter members to the static pressure within drum 52 on the left side of pump member 70, as viewed in the drawing, may be increased until the pump member '78 is shifted axially into engagement with the clutch disc 88. This causes the clutch disc 88 to drivably engage the transverse wall of the drum 52 thus accommodating the transfer of power from the engine driven fiy wheel 20 to shaft 116 and to the power output shaft 118 thus bypassing the planetary gear portion of the transmission mechanism.

To obtain reverse drive, the brake band 160 is energized thus holding brake member 1.34 stationary and the brake band 156 is simultaneously released. The brake member 134 is positively connected to sun gear 68 as shown at 162 thus holding the turbine member stationary. Since the carrier member 114 of the planetary unit 12 is no longer held stationary, the reaction torque on the reaction member 10% of the converter unit 16 causes carrier member 114 to rotate in a reverse direction. Since sun gear 68 is held stationary, the rotation of the carrier 114 will be accompanied by a reverse driving motion of the sun gear and the power output shaft 118. By preference, the torque multiplication ratio of the transmission in reverse is equal to approximately 2.50 so that the total torque multiplication ratio for the transmission is equal to 2.50 times the converter torque ratio.

It is thus apparent that I have provided a hydroltinetic transmission mechanism of simplified construction wherein the reverse torque normally applied to the reaction member of the hydrokinetic unit may be utilized to obtain reverse drive thus eliminating the need for a separate reverse gear and wherein direct drive may be obtained by directly clutching the pump member to the power output portions of the mechanism. No special clutch plates or clutch actuators are required since the existing transmission components are effectively utilized as the constituent elements of the direct drive clutch.

Although I have particularly described one preferred embodiment of my invention, I contemplate that variations therein may be made without departing from the scope of the invention as defined by the following claims.

What I claim is:

1. In a multiple speed power transmission mechanism for delivering power from a driving shaft to a driven shaft, a hydrokinetic unit comprising a pump member and a turbine member, said members collectively defining a; least in part a fluid circuit for accommodating the circulation therethrough of a hydraulic medium, a positive connection between said pump member and said driving shaft, an epicyclic gear unit comprising a plurality of compounded gear elements, one of said gear elements being connected to said driven shaft, a second of said gear elements being connected to said turbine member, brake means for selectively restraining the motion of a third of said gear elements and for absorbing the torque reaction accompanying the transmission of torque through said gear unit whereby a first driving speed ratio is obtained, clutch means for directly coupling said driven shaft and said driving shaft to obtain a second driving speed ratio, and servo means for energizing said clutch means, said servo means being defined in part by said pump member.

A ;.power 1 transmission :mechanism comprising a driving shaft, a .=tii"iven.- shaft, a 1, gear :unit ,includingtazpluralityxof compounded-gearetements, a'hydrokinetic Iunit -:comprising1a pump: member and a turbine member defining at least in part a fluidtpath fonaccommodatingthe the ':latter .:-being :adapted to be hydraulically :loaded to produce an energizing iforceafon said;clutch means.

3. Inuaepower transmission mechanism :comprising a driving 1 shaft, .=a driven shaftpan"epicyclic igear' unit includingiaprimaryand at secondary:sun:gear,;a planet gear carrier, planet gears :carried'iby said carrier :in engagement with said sun .gears,.a 'hydrok1'netic torque converter rcomprisingapump member, a turbine-member and a reactor member, said :members zdefining a :hydrokinetic =fluid circuit, said pumpr'memberibeingimechanically:connected to said driving shaft said turbinemember being connected to :said primary 3 sun-gear, .said drivenz' shaft ,being iPOSitiV'eIYICOIIIICCtGd" toi'sa'id tsecondary'sun gear, said reactor member TbGI Hg :connected to 'said :carrier,

clutch means. for forming :arpositive: torque :delivery :path between said driving= shaft and ::said-: driven shaft, "brake energizing said clutch means, saidmumpsmember being axially shiftable and defining in part said servo means, said pump member being adapted to'rbe hydraulically loaded in an axial direction to actuate said servo means.

4. In a power transmission'mechanism comprising a idrivingshaft, a driven, shaft, an epicyclic gear:;unit:-com *pri'singfirsttand second gears of different pitch :diameters,

a planet gear carrier, planet gears carried by said carrier in engagement with-said sun gears,'a hydrokinetic torque 'convertercomprising a pump member, a turbinemember and a reactor member, said converter members defining a hydrokinetic fluid circuit, said pump member being positively coupled to said driving shaft, said turbine memher being connected to said first gear, said driven shaft being connected to said second gear, said reactor member being connected to said carrier, clutch means for forming a positive powered connection between said driving shaft and said driven shaft, first brake means for holding said carrier and for restraining movement of the same, second brake means for selectively braking said turbine member and said first gear, and servo means for selectively energizing said clutch means, said servo means being defined in part by said pump member, the latter being adapted to be hydraulically loaded to produce an energizing force for said clutch means.

5. In a power transmission mechanism comprising a driving shaft, a driven shaft, a gear unit, a hydrokinetic unit including a pump member and a turbine member, said turbine member being connected to a portion of said gear unit, another portion of said gear unit being connected to said driven shaft, said pump member being connected to said driving shaft, clutch means for selectively clutching together said driving shaft and a portion of said gear unit for conjoint movement, and a servo means for energizing said clutch means, said pump member having axially shiftable portions and defining in part said servo means whereby said clutch means may be energized by hydraulically loading said pump member in an axial direction.

36. 111 aitpower t-ransmission mechanism .1 comprising; a

Jdriving m'embernazdriven member, aigearzaunit, ,athydrokinetic unit including a'tpump member and a turbine member, said turbine member :being; connection to :a :portion of said =-gear- :unit," anoth'er'portioniof said :gearouiiitr being connected to said driven member, said :pump :member including clutch surfaces formed ontsaid'pumpumember and on-said driving member in:juxtaposedrelationship, a clutch :member positively vconnected ito .zsaid idriven s r nember' including 21a friction element situated between said friction surfaces, andwmeansJ-for hydraulically "loading said' pump member toi effect an axialxshiftingmovement of lthe same thereby'i urging said: friction :surfaces into engagement withisaid friction element to :provide tmeans :for selectively: holding :said :carrier :and i: for -restraining; movement of ':the usamefaandservormeans Infor a driven connection betweenvsaid driving member and saidpump -member.

7. ln ar powertransmission mechanism comprising; a

driving portion, \ad riven spor'tion', .a i gear :unit, ia:' hydro- I kinetic:power"transmitting-innit :includinga apump member'tand .a turbine 'member defining athydrokinetici fluid circuit, said" turbine: member being connected" toaonet .portion of said gear unitganother portiontoffsaid gear unit beingiconnected .to --said 'driven'portion, ranmechanical element-i disposed b'etweenx'said housing1and ".said pump,

* said driven portion :includingua :power output "shaft .1 and ta coupling shaftinterconnecting saidtzpowersoutput.shaft and --said clutch mem'ber, :andtmeans:for'subjectingzsaid pump member to an-' axial shifting" force to provide; a

driving conne'ction through said clutch .member"frorn said driving :portion to' said power-output "shaft.

-8. Thecombination setlforthiin claimq whereinesaid :driving Y portion includes a :cylindrical @wall surrounding :said "pump, said pump 1 member being axially shiftable -with respect I to said: driving Ipontion wvith' tthe periphery ithereof in settling engagement'with said'surrounding cylindrical wall :and whereina'saideclutch member 'rin'cludesr a i hubnportion extending axially through said: pump :mem- I iber in concentric relationship therewith.

9. Inlia'-power 'transmission "mechanismecomprising a a driving portion, a driven portion, a gear unit, a hydrokinetic power transmitting unit including a pump member and a turbine member defining at least in part a hydrokinetic fluid circuit, said turbine member being connected to one portion of said gear unit, another portion of said gear unit being connected to said driven portion, a mechanical connection between said driving portion and said pump member, said connection being adapted to accommodate a relative axial shifting movement of said pump and said driving portion, the latter defining in part a cylindrical wall surrounding said pump member, a clutch member including a friction element disposed between said housing and said pump, said driven' portion including a power output shaft and a coupling shaft interconnecting said power output shaft and said clutch member, and means for subjecting said pump member to an axial shifting force to provide a driving connection through said clutch member from said driving portion to said power output shaft, said pump member being axially shiftable with respect to said driving portion with the periphery thereof in sealing engagement with said cylindrical Wall and wherein said clutch member includes a hub portion extending axially through said pump member in concentric relationship therewith.

10. In a power transmission mechanism, a driving member, a driven member, a hydrokinetic unit comprising a pump member and a turbine member, said pump and turbine members defining at least in part a hydrokinetic fluid circuit, a gear reduction unit having a portion connected to said driven member, coupling means for drivably connecting said pump member and said driving member with provision for accommodating a relative axial shifting movement of said pump member with respect to said driving member, said turbine member being connected to another portion of said gear unit, and clutch means for directly connecting said driving and driven members including a friction member disposed adjacent said driving member, an intermediate shaft interconnecting said driven member and said friction member, and means for selectively varying the fluid pressure within said fluid circuitto effect an axial shifting movement of said pump member, said pump member drivably engaging said friction member upon movement thereof in one direction to complete a direct power flow path between said driving and driven members.

11. In a power transmission mechanism, a driving member, a driven member, a hydrokinetic unit comprising a pump member and a turbine member, said pump and turbine members defining at least in part a hydrokinetic fluid circuit, a gear reduction unit having a portion thereof connected to said driven member, means for transmitting driving torque from said driving member to said pump member while accommodating a relative axial shifting movement of the latter, said turbine member being connected to another portion of said gear unit, clutch means for directly connecting said driving and driven members including a friction member disposed ad- I jacent said driving member, and means for selectively pressurizing said pump member to effect an axial shifting movement of the same thereby providing a direct driving connection between said driving and driven members.

12. In a power transmission mechanism, a driving member, a driven member, a hydrokinetic unit comprising a pump member and a turbine member and defining in part a first power delivery path, a gear having a portion thereof connected to said driven member, said hydrokinetic unit and said gear unit defining a second power delivery path, means for drivably coupling said pump member and said driving member while accommodating a relative axial shifting movement between the same, said turbine member being connected to another portion of said gear unit, clutch means for connecting said driving member to a portion of said gear unit to establish a second power delivery path between said driving and driven members, servo means for energizing said clutch a fluid pressure force capable of shifting the latter and energizing said clutch means.

13. In a power transmission mechanism, a driving member, a driven member, a hydrokinetic unit comprising a pump member, a reactor member and a turbine member, said pump, reactor and turbine members defining a hydrokinetic fluid circuit, a gear reduction unit having a portion connected to said driven member, means for delivering driving torque from said driving member to said pump member while accommodating a relative axial shifting movement of the same, said turbine member being connected to a. second portion of said gear unit, said reactor member being connected to a third portion of said gear unit, means for alternately and selectively braking said reactor member and said turbinemember to accommodate the transmission of power through said gear unit in one direction and in the opposite direction respectively, and clutch means for directly coupling said driving member to said driven member, said clutch means including a clutch surface carried by said pump member, a friction member positively connected to said driven member, and means for hydraulically loading said pump member to effect an axial shifting movement of the same and to create a direct driving connection between said driving and driven members through said friction member.

14. The combination as set forth in claim 13 wherein said clutch means is further comprised of a clutch disc disposed between said driving member and said pump member, said friction member being carried by said clutch disc in axially adjacent relationship with respect to said pump member and said driving member, and an intermediate shaft interconnecting said driven member and said clutch disc.

References Cited in the file of this patent UNITED STATES PATENTS 2,324,733 Smirl July 20 ,1943 2,695,533 Pollard Nov. 30, 1954 FOREIGN PATENTS 668,839 France July 22, 1929 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION September 9 1958 Patent No. 2 850321 James Knowles ears in the printed specification It is hereby certified that error app 11 and that the said Letters of the above numbered patent requiring oorreotio Patent should readas corrected below.

6" read 118 line 34, for

Column 3,- line 29, for "11 same line for "138" read 68 g "15" read 14 line 44, 44, for 136" read 146 -g; column 4 line 6, for "136" read 146 ---g column 5, line 45,, for "sun" read first and second Signed and sealed this 11th day of October 1960.

(SEAL) Attest: g KARL AXLINE' ROBERT c. WATSON Commissioner of Patents Attesting Officer 

